Bottom for buildings without basement, and a method of making such bottom

ABSTRACT

A bottom for buildings without basement founded on the soil after removal of only the humus layer and a method of making same. A foundation wall of heat and moisture insulating blocks having the same height as the foundation wall and placed in juxtaposition extends along the outer wall of the building, a heat and moisture insulating layer of pellets of burnt expanded clay is placed directly on the soil inwardly of the foundation wall, and a steel reinforced concrete layer is cast directly on top of the layer of pellets of burnt expanded clay using the foundation wall as form side wall, and is integrally united with the foundation wall.

United States Patent Bokvist et a1.

451 July4,l972

[541 BOTTOM FOR BUILDINGS WITHOUT BASEMENT, AND A METHOD OF MAKING SUCHBOTTOM [72] inventors: Kjell Arne Bokvist, Solna; Curt Holger Ingestrom,Linkoping, both of Sweden 211 App1.No.: 831,907

FOREIGN PATENTS OR APPLICATIONS 773,192 4/1957 Great Britain 52/61273,369 6/1960 France .52/439 232,332 4/1925 Great Britain ..94/31457,318 11/1936 Great Britain ..94/3l OTHER PUBLICATIONS ConcreteMasonry Age, 863 E. Leodora Glendora, California, pages 1, l2, and 20ofNovember 1960 Primary Examiner-Frank L. Abbott AssistantExaminer.lames L. Ridgill, Jr. Altomey-lohn Lezdey [57] ABSTRACT Abottom for buildings without basement founded on the soil after removalof only the humus layer and a method of making same, A foundation wallof heat and moisture insulating blocks having the same height as thefoundation wall and placed in juxtaposition extends along the outer wallof the building, a heat and moisture insulating layer of pellets ofburnt expanded clay is placed directly on the soil inwardly of thefoundation wall, and a steel reinforced concrete layer is cast directlyon top of the layer of pellets of burnt expanded clay using thefoundation wall as form side wall, and is integrally united with thefoundation wall.

8 Claims, 6 Drawing Figures PKTENTED JUL 41972 SHEET 1 N 5 SHEET t (If 5o oo o o O M ca Q o 0 0? W\ o o N\ n fiv vM ll Q I P'A'TENTEDJUL'4 19123.673 .750

SHEET 5 OF 5 BOTTOM FOR BUILDINGS WITHOUT BASEMENT AND A METHOD OFMAKING SUCH BOTTOM The purpose of the present invention is to provide afarreaching rationalization of the erection of buildings withoutbasements and to conduct this rationalization as far as possible withdue consideration of the usual requirements as to the heat and moistureinsulation of the bottoms of buildings of this type. In other words, theinvention has for one of its objects to provide, notwithstanding thefar-reaching rationalization, a fully reliable and sufficiently strongbottom for buildings without basement.

Characteristic of the bottom according to the present invention is thatit is founded on soil from which only the humus layer has been removedand which has been levelled and possibly also compacted, and comprisesthe following parts: a foundation wall of prefabricated heat andmoisture insulating blocks following in the plane the extension of theouter walls of the building to be erected and suited to support saidouter walls, the heat and moisture insulating blocks being placed injuxtaposition on the soil and having the same height as the foundationwall; a heat and moisture insulating layer of grains of burnt expandedclay laid within the confines of the foundation wall directly on thesoil from which only the humus layer has been removed and which has beenlevelled; and a layer of steel reinforced concrete cast in situ on topof said heat and moisture insulating layer using the foundation as aform side wall, whereby said layer will become integral with saidfoundation wall and reinforce it, said layer of reinforced steelconcrete being suited as a direct support for the flooring of thebuilding. A bottom of the type defined is attained only if all therequirements stipulated are satisfied at the same time.

The invention will be more fully described in the following, referencebeing had to the accompanying drawings in which FIGS. 1-5 illustrate oneembodiment of the invention and FIG. 6 illustrates another embodiment ofthe invention.

In the drawings:

FIG. I is a cross section, taken at right angles to the longitudinaldirection of the foundation, of one of the heat and moisture insulatingblocks utilized for erection of the foundation wall;

FIG. 2 is a section on line 11-" in FIG. 1, of some of the blocks placedin juxtaposition for erection of said foundation wall;

FIG. 3 is a vertical cross section of the foundation wall and theadjoining portions of the building bottom as well as the aids exploitedin erecting the foundation wall and supporting it during the makingofthe building bottom;

FIG. 4 is a perspective view of part of the foundation wall and theadjoining portions of the building bottom as well as the aids exploitedin erecting the foundation wall and supporting it during the work phasesto be carried out after the erection of the foundation for making thebuilding bottom;

FIG. 5 is a fragmentary vertical section of the finished buildingbottom;

FIG. 6 is a perspective view and section of parts of anodier embodimentof the building bottom.

The nature of the bottom suggested by the present invention forbuildings without basement will appear from the following description ofthe method of making such bottom. The first phase of the making of thebottom comprises prefabricating the heat and moisture insulating blocks1 to be used for the erection of the foundation wall. As theirdesignation is intended to express, these blocks shall have aconsiderably higher combined heat and moisture insulating capacity thanbuilding blocks of steel reinforced concrete and also conventionallight-weight concrete. Particularly advantageous for the purpose of theinvention both from an economical viewpoint and the viewpoint of heatand moisture insulation are blocks of so-called light-weight clinkerconcrete. By the expression blocks of light-weight clinker concrete isto be understood primarily grains or crushed pieces of burnt expandedclay, for instance the material known and commercially available underthe trade mark LECA." Such grains are produced from selected clay whichwith the admixture of organic material hm been burnt to initialsintering in a rotary kiln and which as a result of the admixture of theorganic material effected prior to burning and as a result of theburning being carried out in a rotary kiln displays a blistery structure(mainly closed cells) as distinct from a porous structure (open cells).This material is known to have favorable properties as a heat insulatingmaterial, to possess a heat insulation capacity which is relativelyinsignificantly deteriorated by moisture, and to have a relatively smalltendency of absorbing and conducting moisture. Thus, this material is acapillary breaking material. Light-weight clinker concrete havinglight-weight LECA" clinker as an aggregate is likewise known to possessmuch of the favorable moisture and heat insulating properties of theLECA" material.

Upon erection of a building without basement in accordance with thepresent invention, the excavating work can be restricted, withoutdetriment to a satisfactory heat and moisture insulation of the buildingin relation to the soil, to the removal of the humus layer (in mostcases to a depth of only one or two decimeters) from the soil beneathand in the immediate environment of the building to be erected. Anexcavation to a greater depth for accommodating the conventional gravellayers that break the capillary force thus is not required, nor is anexcavation to a frost-free depth. The soil from which the humus layerhas been removed is then levelled by equalization of height differences,and, if necessary, the soil and the filled-out low points can becompacted. The levelling may be carried out by placing a thin cement orconcrete layer directly on the soil as in the embodiment shown in FIG.6.

In the embodiment shown in FIGS. 1-5 wooden laths 2 are placed on thesoil from which the humus layer has been removed and which has beenlevelled, said wooden laths serving as supporting and aligning means atthe placing of the heat and moisture insulating light-weight clinkerblocks 1 constituting the foundation wall. These supports and thealigning means are laid outside and along the outer contours of the planof the building to be erected and are suitably secured in position bysoil nails (nails having bent upper hook-shaped ends, which are driveninto the soil) as will appear from FIG. 4.

In the embodiment shown in FIGS. 1-5 the prefabricated light-weightclinker concrete blocks 1 have an upwardly open U-shaped groove in theirtop surface. The blocks 1 are placed with this groove facing upwardlyalong the wooden laths 2 in application against the side of said laths.As a result, an upwardly open channel 3 will be formed, which extendsthroughout the length of the foundation wall. The juxtaposed blocks 1are supported on the outer side also by tubular V- shaped elements 4which have one arm secured to the laths 2 and the other arm appliedagainst the outer sides of the bloc ks l constituting the foundationwall. The tubular V-shaped elements 4 are adjustably blocked up by meansof wooden wedges 5, as will appear from FIG. 4. Preferably, the V-shapedelements 4 are provided at their arm ends with angle-iron pieces 6, 7welded thereto. The pieces 6 have nail holes to permit provisionallynailing them to the lath 2 as will appear from FIG. 4.

When all the blocks 1 necessary for the foundation wall have been put inposition a heat and moisture insulating layer 8 of grains or pellets ofburnt expanded clay, preferably LECA" pellets or grains, is spread onthe soil within the confines of the foundation wall. These pellets orgrains may suitably have a grain size of 8-16 mm. The grains of burntexpanded clay can be loosely spread within the foundation wall, but itis also possible to have the heat and moisture insulating layer 8 in theform of a bonded layer of grains of burnt expanded clay. In thelast-mentioned case the grains of burnt expanded clay shall only becoated with a binder, for instance a cement slurry or possibly abituminous binder, so that the communicating passageways between theindividual grains are not clogged by the binder. The heat and moistureinsulating layer 8 may suitably be slightly compacted on spreading.

A layer 9 of steel reinforced concrete suited as a direct support for aflooring is then cast in situ on top of the heat and moisture insulatinglayer 8, the foundation wall formed by the blocks 1 being exploited asform side walls. The concrete layer 9 will thus become integral with andthereby strengthen the foundation wall. At the casting a particularlycareful vibration should suitably be effected in the area closest to thefoundation wall.

In the embodiment shown in FIGS. 1-5, prior to casting the concretelayer 9, reinforcing rods 10 serving as longitudinal reinforcement havebeen disposed in the upwardly open channel 3 in the foundation wall.Also, reinforcing rods 11, preferably in the form of frames embracingthe longitudinal reinforcement 10, have been arranged so as to extendthrough the joints between the blocks 1 into the space accommodating theconcrete layer 9. As a result, said reinforcing rods 11 will be embeddedin the concrete layer 9 at the casting thereof. Prior to, simultaneouslyas or after the casting of the concrete layer 9, concrete 12 is pouredinto the channel 3 for embedding the reinforcing rods 10, 11 in thefoundation wall. This will firmly anchor the foundation wall to theconcrete layer 9 by means of the reinforcing rods 11 arranged in thejoints between the blocks 1. After the concrete layer has set orhardened the aids utilized for externally supporting the foundation wallare removed. They can then be utilized for the erection of anotherbuilding.

As will appear from FIG. 5, the foundation wall formed by the blocks Ican be utilized as a support for the outer walls of the building, afterthe concrete has set. Thus there is shown in the left'hand portion ofFIG. 5 an outer wall of prefabricated concrete elements 13 erected onthe foundation wall with the interposition of insulating board 17, whilethe right-hand portion of FIG. 5 shows an outer wall consisting of aninternal lath work I5 containing a heat insulation 14, and an externalcoat [6 of facade bricks. This outer wall is also placed on thefoundation wall with the interposition of a moisture insulation. Abuilding bottom constructed in accordance with the invention is suitablenot only for one-storied buildings but also for multistoried buildings.

The heat and moisture insulating layer 8 and the concrete layer 9 castin situ on the layer 8 have a sufficient supporting ability to permitsupporting the partitions of the building which are usually constructedas light-weight walls. FIG. 5 also shows the exploitation of theconcrete layer 9 as a direct support for a flooring 18 of parquet,linoleum, asbestos polyvinyl chloride boards or the like.

In the embodiment of the invention described in the foregoing withreference to FIGS. 1-5 the V-shaped elements and wooden laths have beenused for fixation and supporting the prefabricated heat and moistureinsulating blocks constituting the foundation wall, during the castingin situ of the layer of steel reinforced concrete. In the embodiment ofthe invention illustrated in FIGS. 1-5 a longitudinal reinforcement hasalso been arranged in the blocks constituting the foundation wall, andthis longitudinal reinforcement has been connected with the layer ofsteel reinforced concrete with the aid of frame means.

However, the construction of the bottom of the building without basementcan also be further rationalized in that the longitudinal reinforcementand the frame means as well as the supporting structures can bedispensed with if the bottom is designed and made in accordance withwhat is described below in connection with the embodiment of theinvention illustrated in FIG. 6.

As will appear from FIG. 6 the bottom comprises prefabricated heat andmoisture insulating blocks 1 which preferably consist of light-weightclinker concrete blocks. Within the blocks I there have been arranged aheat and moisture insulating layer 8 of grains or pellets of burntexpanded clay which is placed on the soil from which only the humuslayer has been removed and which has been levelled and possibly alsocompacted, and on top of said layer 8 a layer 9 of steel reinforcedconcrete cast in situ with the use of the blocks 1 as a form side wall,whereby said layer 9 becomes in tegral with the foundation wall thusreinforcing it. The em bodiment shown in FIG. 6 differs from that shownin FIGS. 1-5 in that at least the final levelling of the soil from whichthe humus layer has been removed is realized within the area of theextension of the foundation wall by placing on the soil a thin cement orconcrete layer 20 as a planar support for the prefabricated heat andmoisture insulating blocks I. To fully exploit said cement or concretelevelling layer 20 the prefabricated blocks 1 should preferably beplaced on the levelling layer 20 while this layer is still moist andcapable of bonding with the heat and moisture insulating blocks to beunited with them afier setting and hardening.

A still better support for and anchoring of the prefabricated blocksconstituting the foundation wall is realized by providing, as shown inFIG. 6, along the foundation wall and extending over but part of theheight thereof a projecting longitudinal anchoring means or moulding 21which is made integral with and of the same material as the levellinglayer 20. Said moulding 21 should be cast at least on the outer side ofthe foundation wall, but it is preferred to provide such a moulding oneach side of the foundation wall, as is shown in the drawing. In certaincases and particularly when the foundation wall has to carry great loadsit is advantageous from the viewpoint of strength to embed one or morelongitudinal reinforcing rods in said moulding 21. This reinforcementcan also serve to take up temperature strains from the outer wall. Afterthe cement levelling layer 20 and the moulding or mouldings 21 have setthe distribution of the heat and moisture insulating layer 8 consistingof grains or pellets of burnt expanded clay is commenced, whereupon thelayer 9 of steel reinforced concrete is cast with the use of thefoundation wall as a form side wall. At the casting of said layer 9 oneshould in order to realize as good a bond as possible between theprefabricated blocks 1 and the layer 9, thoroughly vibrate the concreteat least in the area adjacent the foundation wall so that the concretepenetrates into the prefabricated blocks thereby providing not only achemical bond but also a mechanical bond between said blocks and thelayer 9 of steel concrete. To increase the contact surface between thelayer 9 and the prefabricated blocks 1 the latter should preferably bedesigned in the manner shown in FIG. 6, that is the facing end surfacesof the prefabricated heat and moisture insulating blocks should bebevelled at the edge facing inwardly towards the layer 9 of steelconcrete. If the mouldings 21 have been reinforced the reinforcementtherein contributes to transferring loads to the concrete bottom.

The mouldings 21 should preferably extend 4O -lOO mm outwardly from thefoundation wall and in an upward direction along it, mm being preferredfor both of these two dimensions.

When the bottom of a building without basement is constructed inaccordance with what is shown in FIG. 6 there arises so strong a bondbetween the layer 9 of steel concrete and the prefabricated blocks 1that the foundation wall can be regarded as an integral part of thelayer of steel concrete, whereby the building will settle almost to thesame extent within all portions thereof when the ground consolidates. Byreason of said strong bond between the blocks 1 and the layer 9 of steelconcrete the heat insulating foundation wall can very well be loadedwith 3 metric tons running meter since the tensile strength as a rule is6-9 metric tons/running meter. A load of 3 metric tons/running meterapproximately corresponds to that provided by a nonsupporting wall of asix-storied building.

It may be mentioned as an example of how far it has been possible toconduct the rationalization according to the present invention that abottom for a building without basement having the outer dimensions of IOX 60 meters can be finished in 8-10 days when the bottom is made inaccordance with FIG. 6, whereas about 3 weeks are required for finishinga continuous slab footing constructed in the conventional manner. Onmaking a bottom designed in accordance with FIG. 6 and having theabove-mentioned dimensions the time consumed for the various workingphases is as follows: removal of humus layer and rough levelling, 2days; fine levelling by means of a cement or concrete layer, placingprefabricated light-weight clinker concrete blocks and casting themouldings of cement or concrete layer, 2 days; laying the heat andmoisture insulating layer of grains or pellets of burnt expanded claywithin the confines of the foundation wall (material consumption about60 mm. of grains of burnt expanded clay), 1 day; placing a reinforcement(grid reinforcement) for the layer of steel concrete cast in situ, aboutI to l 1% days; casting the layer of steel reinforced concrete andgrinding thereof for permitting laying the flooring directly on theconcrete layer, 2 days. On making a bottom designed in accordance withFIG. 6 for a detached house of I35 sq.m. it is actually possible tofinish the bottom in about 8 work hours, a pause being made overnightafter the prefabricated blocks have been placed and the mouldings havebeen cast to permit setting of the cement or concrete levelling layer sothat the prefabricated heat and moisture insulating blocks are anchoredtherein before the remaining work phases are carried out.

We claim:

1. In a building without basement founded on soil from which only thehumus layer has been removed and which has been levelled, a bottomcomprising prefabricated heat and moisture insulating light weightclinker concrete blocks, said blocks having the same height as saidbottom and placed in juxtaposition on the soil so as to follow in theplane the extension of the outer walls of the building; a heat andmoisture insulating layer of pellets of burnt expanded clay, saidinsulating layer being placed within the confines of the row of saidblocks on the soil from which only the humus layer has been removed; anda layer of steel reinforced concrete formed by being cast directly ontop of said heat and moisture insulating layer using said blocks as aform side wall and being integral with said blocks.

2. In the building according to claim 1 including levelling means forlevelling the soil beneath said blocks, consisting of a thin layer ofconcrete.

3. In a building according to claim 2 including longitudinal anchoringmeans along at least the inner side of said blocks; said longitudinalanchoring means being formed integral with said levelling means andextending a short distance in an upward direction on said blocks.

4. ln a building according to claim 1 wherein said heat and moistureinsulating blocks at their facing end surfaces are bevelled at theirvertical edges facing said steel reinforced concrete layer.

5. In a building without basement founded on soil from which the humuslayer has been removed and which has been leveled, a bottom comprisingprefabricated heat and moisture insulating light weight clinker concreteblocks, said blocks having the same height as said bottom and placed injuxtaposition on the soil so as to follow in the plane the extension ofthe outer walls of said building; a heat and moisture insulating layerof pellets of burnt expanded clay, said insulating layer being placedwithin the confines of the row of said blocks; levelling means forlevelling the soil beneath said blocks, said levelling means comprisinga thin layer of concrete; longitudinal anchoring means along at leastthe inner side of said blocks, said anchoring means being formedintegral with said levelling means and extending a short distance in anupward direction on said blocks, and a layer of steel reinforcedconcrete formed by casting said concrete directly on top of said heatand moisture insulating layer using said blocks as side walls and beingintegral with said blocks.

6. In a method for constructing buildings without basements theimprovement which comprises forming a foundation by the stepscomprising:

A. removing only the humus layer from the ground;

B. levelling said ground;

C. placing on said ground in juxtaposition prefabricated heat andmoisture insulating light-weight clinker concrete blocks; D. forming aperipheral row of said blocks following in the plane the extension ofthe outer walls of the building to be erected;

E. placing longitudinal anchoring means along at least the inner side ofthe row of said blocks with said anchoring means also extending upwardlyon said blocks;

F. placing a heat and moisture insulating layer of pellets of burntexpanded clay on the ground within said row of blocks;

G. casting in situ a layer of steel reinforced concrete directly on topof said heat and moisture insulating layer whereby said row of blocksforms a side wall;

H. integrally uniting said concrete layer with said blocks,

and then I. erecting said building whereby the outer wall of saidbuilding is supported by said row of blocks.

7. The method according to claim 6 wherein said longitu dinal anchoringmeans is placed along at least the inner side of the row of said blocksand is formed integral with, and of the same material as said levellingmeans, and extending said longitudinal anchoring means also a shortdistance in an upward direction on said blocks.

8. The method according to claim 6 wherein said step of integrallyuniting said steel reinforced concrete layer with said blocks comprisesbevelling said heat and moisture insulating blocks at their facing endsurfaces at the vertical edge facing said steel reinforced concretelayer.

1. In a building without basement founded on soil from which only thehumus layer has been removed and which Has been levelled, a bottomcomprising prefabricated heat and moisture insulating light weightclinker concrete blocks, said blocks having the same height as saidbottom and placed in juxtaposition on the soil so as to follow in theplane the extension of the outer walls of the building; a heat andmoisture insulating layer of pellets of burnt expanded clay, saidinsulating layer being placed within the confines of the row of saidblocks on the soil from which only the humus layer has been removed; anda layer of steel reinforced concrete formed by being cast directly ontop of said heat and moisture insulating layer using said blocks as aform side wall and being integral with said blocks.
 2. In the buildingaccording to claim 1 including levelling means for levelling the soilbeneath said blocks, consisting of a thin layer of concrete.
 3. In abuilding according to claim 2 including longitudinal anchoring meansalong at least the inner side of said blocks; said longitudinalanchoring means being formed integral with said levelling means andextending a short distance in an upward direction on said blocks.
 4. Ina building according to claim 1 wherein said heat and moistureinsulating blocks at their facing end surfaces are bevelled at theirvertical edges facing said steel reinforced concrete layer.
 5. In abuilding without basement founded on soil from which the humus layer hasbeen removed and which has been leveled, a bottom comprisingprefabricated heat and moisture insulating light weight clinker concreteblocks, said blocks having the same height as said bottom and placed injuxtaposition on the soil so as to follow in the plane the extension ofthe outer walls of said building; a heat and moisture insulating layerof pellets of burnt expanded clay, said insulating layer being placedwithin the confines of the row of said blocks; levelling means forlevelling the soil beneath said blocks, said levelling means comprisinga thin layer of concrete; longitudinal anchoring means along at leastthe inner side of said blocks, said anchoring means being formedintegral with said levelling means and extending a short distance in anupward direction on said blocks, and a layer of steel reinforcedconcrete formed by casting said concrete directly on top of said heatand moisture insulating layer using said blocks as side walls and beingintegral with said blocks.
 6. In a method for constructing buildingswithout basements the improvement which comprises forming a foundationby the steps comprising: A. removing only the humus layer from theground; B. levelling said ground; C. placing on said ground injuxtaposition prefabricated heat and moisture insulating light-weightclinker concrete blocks; D. forming a peripheral row of said blocksfollowing in the plane the extension of the outer walls of the buildingto be erected; E. placing longitudinal anchoring means along at leastthe inner side of the row of said blocks with said anchoring means alsoextending upwardly on said blocks; F. placing a heat and moistureinsulating layer of pellets of burnt expanded clay on the ground withinsaid row of blocks; G. casting in situ a layer of steel reinforcedconcrete directly on top of said heat and moisture insulating layerwhereby said row of blocks forms a side wall; H. integrally uniting saidconcrete layer with said blocks, and then I. erecting said buildingwhereby the outer wall of said building is supported by said row ofblocks.
 7. The method according to claim 6 wherein said longitudinalanchoring means is placed along at least the inner side of the row ofsaid blocks and is formed integral with, and of the same material assaid levelling means, and extending said longitudinal anchoring meansalso a short distance in an upward direction on said blocks.
 8. Themethod according to claim 6 wherein said step of integrally uniting saidsteel reinforced concrete layer with said blocks comprises bevellingsaid heat and moisture insulating blocks at their facing end surfaces atthe vertical edge facing said steel reinforced concrete layer.